Triceratops (IPA: /tɹaɪ'sɛɹətɒps/) was a herbivorous genus of ceratopsid dinosaur that lived during the late Maastrichtian (end of the Late Cretaceous Period) around 68-65 million years ago in what is now North America; it was one of the last dinosaurs to appear before the great K-T extinction event. Bearing a large bony frill and three horns on its large four-legged body, and conjuring similarities with the modern rhinoceros, Triceratops is one of the most recognizable of all dinosaurs. The name Triceratops, which literally means "three-horned face", is derived from the Greek tri -/τρι- meaning "three", ceras/κέρας meaning "horn", and -ops/ωψ meaning "face". Though it shared the landscape with, and was preyed upon by, the fearsome Tyrannosaurus, it is unclear whether the two battled the way they are commonly depicted in movies and children's dinosaur books.
Although no complete skeleton has been found, Triceratops is well-known from numerous partial specimens collected since the genus' introduction in 1887. The function of their frills and three distinctive facial horns has long inspired debate. Although traditionally viewed as defensive weapons against predators, the latest theories suggest these features were primarily used in display for courtship and dominance, much like the antlers and horns of modern reindeer, mountain goats or rhinoceros beetles.
Triceratops is the best-known of the ceratopsids, though the genus' exact placement within the group has been a point of contention amongst paleontologists. Two species, T. horridus and T. prorsus, are considered valid, although many other species have been named.